Fully or semi synthetic?

Bought 5L Mobil Super 3000 Formula FE 5W-30 on 2nd June at your Leicester store believing it to be fully synthetic, which was what I wanted. I now see on your Spec tab it is described as semi synthetic, yet it5 is clearly labelled by Mobil as "Fully Synthetic Motor Oil". What is going on? I wanted a fully synthetic oil for my car and thought this was I had got. Who is right?

this oil was Formerly Mobil Synt S 5W-30. But now the range has been changed to fully synthetic. I believe that the spec sheet is out dated as it clearly is marked fully synthetic on the oil can